1850.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



95 



Required from the nhove Elements, 



1. To determine the radius of the curve which shall pass throuc:h 

 the three points a\ a, a', and wliicli shall tangent the soffits of tlio 

 five segment arches. 



2. To determine by calculation the span of each of the five seg- 

 ment arches, which shall, when added together, give a waterway of 

 ()70 feet in width; and, with the tliickness of tlie four piers, 76 feet 

 broad, a space of 7+6 feet in widtli between the abutments or points 



c, c. 



3. To determine by calculation the versed sines of each of tlie 

 five arches. 



■t. Tlie soffits of the five segment arches to tangent the curve 

 line which shall pass thri)ugli the tliree points «', a', a. 



5. The length of the radius whicli shall be common to the five 

 segment arches contained between the springing line 6, b. A, 6, and 

 tlie curve line passing throuj^h the three points a, a, a'. 



February, 1850. B. 



THE SMYRNA STEAM FLOUR-MILLS 



AND 



THE M^ATT AND AVOOLF STEAM-ENGINES. 



On Saturday, the 19th of January last, a private view of two power- 

 ful steam-engines, on tlie Woolf principle, but with oscillating cylin- 

 ders, took place at the works of the Messrs. Joyce, engineers, 

 Greenwich : we would rather say, a public view, the admittance 

 being by invitation and by c;ird. We were invited to be present, 



but could not attend, the pressing nature of our avocations having 

 prevented us. Since then, accounts of those steam-engines have 

 a]ipeared in the columns of several of our contemporaries ; and 



from one of them, the Mining Jnurnal, we shall take leave to extract 

 tlie following: — 



'* Tlie engines which the Messrs. Joyce have constructed for this purpose, 

 have been formed upon a principle entirely new in this country, which has 

 heen found to work with unexampled advantage in several establishments ia 

 which the same kind of engines has been adopted. In their general arrange- 

 ment, they may he described as belonging to the class of steam-engines 

 termed " oscillating," from the circumstance of their cylinders vibrating on 

 axes or trunnions, in order that the piston-rods may constantly act upon the 

 cranks without the intervention of what in stationary engines is termed a 

 p;uallel motion, a contrivance, by which the vertical motion of the piston- 

 rod is adapted to the circular motion of the cranks. The principle disco- 

 vered by Woolf, of introducing steam of a high-pressure into a small cylinder, 

 and allowing it to act expansively in a larger one at a pressure smaller than 

 the original, in the proportion of the circular sections of the cylinders, and 

 afterwards to add to its etfective force by condensation, is here applied in au 

 extremely ingenious manner, and with a simplicity of arrangement having 

 reference to the multiplicity of objects which are to be provided for simul- 

 taneously in the machine. But what Woolf did hy the intervention of parts 

 which rendered the action indirect, is here done without the aid of subsi- 

 diary arrangements, and the action is direct. The oscillating cylinders are 

 for this purpose inverted, and vibrate upon steam-ways at their upper extre- 

 mities. The long horizontal shaft upon which the piston-rods act, ia fur- 

 nislied with cranks, so that the riead point is always got over, and the 

 motion traiisniitted hy cogged-wheel gearing, the large wheel being 16 feet 

 ni diameter — the fourteen mills, each of which is furnished with a pair of 

 millstones, grinding in the usual way. 



A report from Mr. Elijah Galloway. C.E., who was employed by Mr. T. 

 Comer, to examine the machinery for him, is now before us, from which we 

 gather, ttiat the capacity and dimensions of the engines and machinery are 

 in all respects, more than ample both for power and strength — the engines, 

 moreover, being equal to nearly double the power required. With reference 

 to the four boilers employed to generate the requisite quantity of steam, Mr, 

 Galloway expresses his ccnviction lliat one alone will be nearly capable of 

 supplying both engines, thus atfording the command of full tliree times the 

 power required, and which would, in his opinion, work safely at " double the 

 proposed maximum pressure." The report concludes with expressing tlie 

 great satisfaction on bis part of the economy attendant on the application 

 of the machinery, and the nicety and perfection with which it has been 

 constructed. 



In the course of conversation we were given to understand that an engine 

 of 12-borse power, at the Greenwich Iron Works, upon the principle referred 

 to, costs only 3ils. per week for 12 hours per day, while several establish 

 ments at home and abroad, prove the consumption of fuel to be less than 

 31b. per hurse power per hour." 



Similar accounts to the preceding have appeared in the other 

 publications to which we have had occasion to allude. Those 

 accounts are of so extraordinary a nature, and so apt to impress 

 the public mind, either with error or doubt — error with those who 

 do not thoroughly comprehend the construction and p.rinciples of 

 the steam-engine, and doubt with tliose who do — that we feel 

 ourselves impelled, by a sense of public duty, to make some 

 comments. 



This course appears to us to be tlie mure incumbent — the more 

 imperative, as it shadows forth a matter of considerable interest at 

 this present time — the comparative value of the Watt and the 

 Woolf steam-engines. 



In the cotton-spinning districts of Glasgow and Manchester, 

 many Woolf-engiiies have been erected recently ; and others, by 

 the addition of another cylinder, and by working the steam at high 

 pressure in the new cylinder, and expanding it in the old, have 

 been changed into Woolf-engines. 



These introductions and adaptations have taken place since the 

 Woolf-engine lias been re-patented liy Mr. MacNaught, of Glas- 

 gow ; and, as we have received letters from several gentlemen, 

 interested in cotton-spinning, claiming our particular attention to 

 the matter, which is of importance to them, we shall now enter 

 upon the subject. 



In the foregoing accounts it is stated, that the Jlessrs. Joyce, 

 the engineers of Greenwich, liave made a pair of magnificent and 

 powerful steam-engines, with all the apjiurtenanees of a flour-mill, 

 to work fourteen pair of stones ; that " the engines are on the 

 douhle-cy/inder expansive plan, originally patented by ^V'oolf;" that 

 " tlie Messrs. Joyce have succeeded in giving a direct action to 

 that wliich Woolf and his followers gave indirectii/, by which, 

 amongst other beneficial results, tlie consumption of fuel is less 

 than 3 lb. per horse power, it being about 12 lb. under the old system;" 

 and that " these results have lieen main!// cchiered by tlie introduetion 

 of a system of inverted and cscillating cylinders, which cause the force 

 of the piston-rods to act directly upon the crank-pin, without the 

 interposition of any intermediate machinery, so that the friction of 



U* 



